Emergency ladders have been used for many years. Multi-storied buildings are sometimes equipped with emergency ladders of various types such as fire escapes. Boats may have emergency ladders to assist in returning a person overboard back onto the boat. Most of these ladders tend to be bulky one-piece rigid ladders which take up too much space.
Rope ladders are known, but are often stored away from where they are needed. Thus, in the situation where a person on a boat falls overboard and where there is no one on board the boat to get the rope ladder or any other safety device, the overboard person may have no way to reboard the boat. What is needed is an emergency ladder system which is compact and which is stored in an always convenient position accessible to the overboard person.
U.S. Pat. No. 4,788,926 overcomes some of the deficiencies of the earlier prior art by providing a combined boat fender or bumper and emergency rope ladder. The rope ladder is contained inside and is part of the fender, and when a person falls overboard he can pull on a handle which causes the bottom of the fender to drop down releasing a rope ladder for egress back onto the boat.
A major deficiency of the '926 bumper is that it is located outside the bounds of the vessel. Thus, it will not be available as an emergency ladder when the bumper is being used as a bumper. For instance, if the bumper is tight against an adjacent boat or a dock, there may be only 3 to 4 inches clearance, not enough for use of the emergency ladder.
If the bumper is dragged in the water such as when heeling while sailing, the ladder may inadvertently deploy.
The bumper is not a permanent installation and must be set in place for use. Safe boating practice dictates that no portable bumpers should be outside the bounds of a vessel when approaching a dock in order to prevent the bumper from getting caught on a piling or another boat. Thus, the bumper/ladder will not be available for emergency use at that time.
Moreover, if the bumper is inadvertently hung on a life line, as is common practice for most bumpers, it probably will not be secure enough for a person to climb aboard.
Also, the knot used to secure the bumper may not hold firmly against a person's weight. This latter problem becomes more clear when it is understood that the handle which must be activated to release the ladder from the bumper shell of U.S. Pat. No. '926 is likely to require significant force for disengagement.
In the bumper ladder system, the bumper is part of the ladder reboarding mechanism. Thus, the whole structure must be strong enough to support a person. This will require that every part of the structure be made of very strong and expensive materials.